Combined recording and reproducing device



Feb. 26, 1935. A, A. THOMAS 1,992,893

COMBINED RECORDING AND REPRODUCING DEVICE Filed March 24, 1931 2Sheets-Sheet l INVENTOR Feb. 26, 1935. A A, THQMAS 1,992,893

COMBINED RECORDING AND REPRODUCING DEVICE Filed March 24,'1931 2sheets-sheet 2 INVENTOR @WMM Patented Feb. V26, 1935 UNITED STATESPATENT OFFICE Adolph A. Thomas, New York, N. Y., assignor to RadioCorporation o! America, a corporation of Delaware Application March 24,1931, Serial No. 524,856

20 Claims.

My invention relates to the art of recording and reproducing sound, andits object is to provide a unitary electric device which carries twoseparate stylus members, one adapted to operate as a recording tool andthe other as a phonograph needle. This device is readily adjustable onits support to bring either stylus member into playing position.

In home recording machines that have hitherto appeared in the market,the electric pickup is also used for recording, but it is necessary toremove the reproducing needle and insert a recording stylus. Then, aftera record has been made, the cutting stylus must be taken out and aplaying needle inserted. VThisv changing of stylus members isbothersome, and there is the further objection that the loose recordingstylus is easily lost or misplaced. Also, in those prior machines, thereis a loose weight which is supposed to be placed on the pickup casingwhen making a record, because the cutting stylus must be held in thepreformed groove of the blank disk with a certain amount of pressure. Aloose weight like that is easily forgot, especially when not insight,and in a house where there are children itis liable to become lost ormislaid. Then, too, a person (especially a child) may drop the looseweight on a record and break the latter.

The foregoing and other objections and disadvantages in prior homerecording machines are overcome by the combined recording andreproducing unit of my invention, in which the presence of two separatestylus members makes it unnecessary to substitute one for the other.This double-acting device is always in condition for recording orreproducing, it being only necessary to adjust it to proper position onits supporting arm. This is so simple that even a child can do it. Thesupporting arm of the recording and reproducing unit preferably carriesa weight which can be swung forward to rest on the unit or rearward intoinoperative position.

The novel features and practical advantages of my invention will befully understood from a description of the accompanying drawings, inwhich:-

Fig. 1 is a side view of my recording and reproducing device shown inrecording position, certain parts being sectioned for clearness;

Fig. '2 represents an enlarged plan view in section on line 2-2 of Fig.1;

Fig. 3 shows a vertical section on line 3,-3 of Fig. 2;

Figs'. 4, 5 and 5a are transverse sections on lines 1 -4, 5-5 and 5dr-5arespectively, of Fig. 3;

Fig. 6 is a side view of a modified form of Amy invention, the devicebeing in reproducing position;

Fig. 'I shows the inside mechanism, partly sectioned, of the modifiedconstruction;

Figs. 8 and 9 represent sectional views on lines 8-8 and 9-9,respectively, of Fig. '7; and

Fig. 10 shows the device of Figs. 6-9 in recording position.

Referring to the construction illustrated in Figs. 1-5, the combinedrecording and reproducing unit comprises a casing 10 adjustably mountedon a supporting arm 12. The casing 10 in the present instance is a iiatrectangular box closed at one side by a removable plate 13, which isattached to the' body of the casing in any practical way. The parts 10and 13 are made of nonmagnetic material, such as brass, aluminum,duralumin, and the like; or they can be molded of composition materialconsisting of phenolic condensation products. For lightness anddurability I prefer to make the casing parts 10 and 13 of aluminum orits alloys, and the box section can be shaped from sheet material in asingle operation. The cover plate 13 terminates at the rear in avertical wall 14, which is provided with a hub 15 adapted to rit intothe front end of the supporting arm 12. The parts 14 and 15 may be castor molded as integral extensions of cover plate 13.

The hub 15 acts as a rotary bearing for the casing 10 and permitsadjustment of the recording and reproducing unit to either of twooperative positions, as presently will be explained. The rotaryadjustment of casing 10 on the supporting arm 12 is limited toapproximately 180 degrees or half a, revolution. Any practical means maybe employed to limit the movement of casing 10 and hold it rmly ineither position. By way of example, I have shown the supporting arm 12provided With a radial slot 16 through which projects a set-screw 17carried by the hub 15 of casing 10. As shown in Fig. 5, the slot 16encompasses an arc of a little more than 180 degrees, so that the axisof set-screw 17 moves through half a circle when the casing 10 isadjusted from one position to the other. The underside of arm 12 carriesa small housing or thimble 18 in which a yieldable pin 19 is movablymounted. An expanding coil spring 20 in housing 18 tends to push the pin19 upward into a pair of rounded notches or recesses 21 of hub 15. Thesenotches are arranged 180 degrees apart, so as to receive the rounded endof pin 19 when the casing 10 is in either one of its two operativepositions. In other words, the springrotary sleeve is journalled. Asetscrew 26 on post 24 projects into an annular groove 27 in sleeve 25to hold the latter against axial movement without interfering with itsrotational adjustment during the making or playing of arecord.

The roary sleeve 25 has a top plate 28 adapted to rest on the upper edgeof post 24, and a pair of spaced ears or lugs 29 on the top platesupport a cross-pin or stud 30 between which the arm 12 is provided. Itwill be seen that the supporting arm 12 is capable of horizontalswinging movement about the rotary sleeve 25, and also has the necessaryvertical movement about the horizontal cross-pin 30. Any other practicalmounting for arm 12 may be used in place of the one above described.

A U-shaped permanent magnet 31 is mounted rigidly on the base plate 13of casing 10 in any practical way, as by screws 32. Two U-shaped polepieces 33 and 34 are secured to the ends of magnet 31 by magnetic screws35, or otherwise. The pole pieces 33 and 34 are preferably made of softiron or other metal having a high magnetic permeability. The ends ofpole pieces 33 and 34 are usually tapered and provide a pair of alignedairgaps 36 and 37. At least one of the pole pieces 33-34 carries a coil38, but I' prefer to add a second coil 39 on the other pole piece. Thesecoils are preferably connected in series and arranged at opposite sidesof the airgaps 36-37, as will be clear from Fig. 2. If necessary, thefront end of casing 10 and the base plate 13 are shaped to providerecesses 40 and 41 for accommodating the coil or coils 38-39. The widthof the permanent eld magnet 31 may be practically the same as that ofbase plate 13, so that the sides of casing 10 fit snugly against thesides of the magnet. This arrangement permits the use of a magnet ofmaximum Width, and at the same time serves to strengthen the sides ofcasing 10, so that the latter can be made of thin sheet material.

A T-shaped non-magnetic bracket indicated as a whole by 42 is secured tobase plate 12 by one or more bolts 43, and the ends of the bracket maybe attached to magnet 31 by screws 44. The bracket 42, which may be usedto hold the magnet 31 in place Without the screws 32 and 44, has anintegral arm 45 extending forwardly and provided ,at its free end withan open slot 46. As shown in Fig. 2, the slot 46 is arranged at an angleand terminates in a shouldered recess 47 adapted to receive one end of aspring blade or shaft 48. The other end of spring blade 48 is mounted ina shouldered recess 49 arranged at the inner end of an open slot 50 inbase plate 13. As shown in Figs. 2 and 4, the shouldered recesses 47 and49 slant in opposite directions at a slight angle, so as to maintain thespring blade 48 in twisted and tensioned condition. The open slots 46and 50 in bracket arm 45 and base plate 13 permit easy insertion ofspring blade 48, which is automatically twisted and tensioned when theends of the spring snap into the slanting recesses 47 and 49. Theserecesses also lockte spring blade in position without the need of extrafastening means. To prevent axial displacement of spring shaft 48, theshouldered recesses 47 and 49 are covered by small plates 51 and 52secured to arm 45 and base plate 13 respectively.

A magnetic armature bar 53 is secured to the central portion ofresilientshaft 48 in any practical way, :1nd the ends of the armaturebar extend into the aligned airgaps 36 and 37, as best shown in Fig. 2.The initial set or tension of spring 48 normally holds the ends of thearmature bar 53 substantially midway in airgaps 36-37, so that thearmature bar is capable of vibrating about the spring without strikingthe pole pieces. 'I'he normal balanced position of armature 53 is alsodue to the balancing effect of the normal flux of field magnet 31. Itwill thus be clear that the twistable spring 48 not only supports thearmature 53, but also acts as resilient restoring means for thearmature. It is evident from Fig. 2 that the oscillatory vibrations ofarmature 53 produce flux variations in coil or coils 38-39. Conversely,when current impulses pass through the coils, the normal eld flux is sounbalanced as to cause vibration of armature 53.

The tensioned spring blade 48 also carries an extension 54 to which avertical arm 55 is attached at the center. If desired, the parts 54 and55 may be formed as a single member, preferably of light material likealuminum. The ends of arm 55 carry holders 56 and 57 adapted to receivea recording stylus 58l and a reproducing stylus 59, respectively. Athumb-screw 60 or other sutiable means holds each stylus removablyclamped in its holder. The recording stylus 58 is a sharp piece of hardmetal, composition or mineral adapted to cut a soundV groove in a diskrecord 61, While the latter is rotated on a turntable 61'.. In practiceit is usual to provide a record blank having a preformed spiral groovein which the point of stylus 58 is placed. The preformed groove acts asa guide for the stylus, and the lateral vibrations of the latter bycurrent impulses in coils 38--39 cut undulations in the side Walls ofthe groove in accordance with the transmitted sound waves. The materialof the record is suiiciently soft to permit cutting of the sound grooveby the recording stylus. v

The reproducing stylus 59 is an ordinary phonograph needle adapted toreproduce from a record made by recording stylus 58 or from any otherrecord. The movements of needle 59 in the record groove causeoscillatory vibration of armature 53, and the resulting current impulsesin coils 38-39 are amplified to give loud-speaker reproduction. There isno need to show any circuit connections for coils 38--39, because thoseare Well understood, and furthermore they form no part of my invention.When changing from recording to reproducing, or vice versa, it is onlynecessary to turn the casing 10 on arm 12 from one position to theother, as previously explained. While the reproducing needle 59 issupposed to be renewed frequently to prevent undue wear on the record,the recording stylus 58 will last a long time and will seldom requireattention. In fact, it is possible to make a recording stylus that willlast for years, if the record blanks are wax or similar material that iseasily cut. The circuit wires for coil or coils. 38--39 may beunited ina cable 62, which passes from casing 10 through the hollow tubular arml2 and sleeve 25 into the space below the motorboard 23. y

It has been found in practice that, when making a sound record on ablank disk, the recording stylus 58 `requires a certain amount of extrapressure to hold the cutting point firmly in place on the disk. On theother hand, when reproducing from a record, the pressure on the needle59 should be comparatively light-not more than a few ounces, and it mayeven be less than an ounce. In prior machines for making phonographrecords at home, it has been necessary to supply a loose weight whichthe operator is supposed to put on the pickup casing during rtherecording operation. This weight must be taken off when playing from arecord. As explained in the introductory part of this specification, aloose weight is objectionable and I dispense with it by providing aweight 63 which is adjustably connected to the pivoted arm 12. In thepresent embodiment of my invention, the weight 63 is fixed on `one endof a rod or link 64 which is pivoted at 65 on a collar 66. This collaris either clamped around arm l2 in a permanent position, or it may beslidably adjustable along the arm. In the latter event, a set-screw 67is used to clamp the collar 66 in adjusted position. The dotted outlines66a and 66h in Fig. 1 indicate different positions of collar 66.

During the recording operation, the weight 63 is swung forward on top ofcasing 10 where it exerts the necessary amount of increased pressure onthe recording stylus 58. During the reproducing operation, the weight 63is swung to the rear of arm l2 into the position indicated by the dottedoutline 63a. It will be noticed in Fig. 1 that the weight in its rearposition 63a acts as a counterbalance for the weight of the ymechanisminside of casing 10, so that the pressure on the reproducing needle 59is reduced to a few ounces. This reduced pressure on the needle pointnot only prevents undue wear on the record, but also lessens theso-called needle noises. It is clear from what has been said that theadjustable weight 63 performs the double function of increasing thepressure on the recording stylus 68 and lessening the weight of the uniton the reproducing needle 59. There is no possibility of the weight 63being left by chance on casing 10 during the reproducing operation,because the weight must be swung to the rear before the casing can beturned from recording to reproducing position. By adjusting the collar66 axially on arm 12, the effective pressure and counterbalancing actionof weight 63 in its two positions can be regulated for the best resultsin any particular machine. If no counterbalancing effect of weight 63 isrequired when it is thrown back, it is only necessary to make the rod 64of such length that the weight will not project beyond the pivot pin 30in its rear position.

In the modification shown in Figs. 6-10, the recording and reproducingunit is housed in a casing 68, which is provided with a separable ycover plate 69 held in place by screws or bolts 70.

What has been previously said about the casing parts l0 and 13 in Figs.1-4 is applicable to the casing parts 68 and 69. Since the constructionand mounting of arm 12 in Figs. 6-10'are the same as those previouslydescribed for the supporting arm in Figs. l, 2 and 3, it will not benecessary to repeat that description. Also, everything previouslyexplained in connection with the adjustable weight 63 is applicabletothe weight shown in Figs. 6 and 10. For reasons that will presentlyappear, the casing 68 need only be rotated through an arc of ninetydegrees on arm 12 to change from recording to reproducing position andvice versa. For this purpose the casing 68 is provided with a hub 71which nts over the free end of arm 12, and this hub is provided with aradial slot 72 arranged to receive a set-screw or pin 73 attached to thearm. The slot 72 permits rotation of casing 68 through an arc of ninetydegrees, and suitable means (like the springpressed pin 19 of Fig. 3)may be provided to hold the casing lrmly in each position.

A U-shaped permanent magnet 74 is mounted on base plate 69 and issecured thereto by a nonmagnetic cross-bar 75. One or more screws 74'may be used to attach the magnet directly to the base plate. A screw orbolt 75a connects the cross-bar 75 to base plate 69, and shoulders 75hon the cross-bar engage the inner sides of the magnet to lock the latteragainst movement. If desired, the ends of cross-bar 75 may be connectedto the magnet by screws 75e. Two pole pieces 76 of high magneticpermeability are secured to the ends of magnet 74 in any practical way,as by screws or rivets 77. The pole pieces 76 are in the form ofstraight bars which carry one or two coils 78, preferably connected inseries. The coils can be machine-wound and slipped over the ends of polepieces 76 where they are held in position by cross-pins 79 or otherwise.The base plate 69. is provided with a pair of lugs 80, which may beintegral with the plate if the latter is cast or molded. The lugs 80carry adjustable bearing screws 81 adapted to support a block ortrunnion 82 for oscillatory movement. The trunnion 82 constitutes acommon pivotal support for three arms 83, 84 and 85. The upwardlyextending arm 83 carries a pair of magnetic armature bars 86 and 87arranged on opposite sides of the polar extensions 76 and on oppositesides of coils 78. The armature bar 87 is notabsolutely necessary andmay be omitted, but II believe its presence increases the efficiency ofthe device, particularly when reproducing. The arm 84 projects through aslot 88 in casing 68 and carries a holder 89 adapted to receive therecording stylus 58. The arm 85 projects through a slot 90 in casing 68andcarrles a holder 91 for receiving the reproducing needle 59. What hasbeen previously said about the stylus members 58 and 59 in connectionwith Figs. l, 2 and 3, applies to the same stylus members in Figs. 6-10.

When the casing 68 is turned horizontal, as shown in Figs. 9 and 10, therecording stylus 58 is in operative position on a record blank 61mounted on turntable 61. The sound to be recorded is convertedintocurrent impulses suitably amplied and sent through coil or coils 78,and these current impulses vary the magnetic flux across the two pairsof airgaps 86 and 87' (see Fig. 9), thereby causing vibration of arm 83.The vibrations of arm 83 cause the vertical arm 84 and recording stylus58 to vibrate laterally in relation to the surface of the record disk.When the reproducing stylus 59 is in operative position, the lateralvibrations.

thereof produced by the undulationsl in the sound groove cause thearmature unit 86-87 to vary the argaps 86-87 and thereby induce electricimpulses in the coils 78. These impulses are suitably amplified tooperate a loudspeaker device, as will be understood without furtherexplanation. As previously suggested, the armature bar 87 may bedispensed with, but it has certain advantages during the reproducingoperation, because it shunts the magnetic lines of force away from coil78 when the arm 83 rocks toward the left. as viewed in Fig. 8. On theother hand, when the arm 83 rocks toward the right, the approach of theupper armature 86 to the pole pieces 76 causes a sudden increase in thefield flux through coils 78.

I provide novel centering or restoring means for the armature unit 86-87in the form of elastic blocks 92 arranged on oppositesides of thepivoted arm 83, as best shown in Fig. 81. The elastic blocks 92, whichmay be cylindrical pieces of india rubber, are held in sockets 93, andthese sockets are adjustably supported on casing 68 andbase plate 69.For this purpose, the sockets 93 have screw extensions 94 which arerotatably adjustable in their respective supports by means of anordinary screwdriver, and lock nuts 95 hold the sockets securely inadjusted position. The elastic blocks 92 are under initial compression,so that they exert opposite pressures against the arm 83 and therebyhold the amature unit 86-87 at substantially equal distances from theintermediate pole pieces 76. The elasticity of the compressed centeringblocks 92 does not interfere with the vibratory movements of arm 83, butthey damp the vibrations of the arm and prevent parasitic movementsthereof. The arms 84 and 85 project through the casing 68 at the propertrailing angle. When viewed from the front of the casing, the arms 84and 85 are in the form of a bellcrank or right-angled lever, as will beclear from Fig. 8. Since one of the screw extensions 94 and its lock-nut95 project beyond the outer surface of base plate 69, one side of theweight 63 may be provided with a groove 69 to receive the projectingparts 94 and 95, as shown in Fig. l0. This arrangement permits theweight to lie flat on top of casing 68.

Although I have illustrated and described certain specificconstructions, I want it understood that my invention is not limited tothe details set forth. Changes and modifications.

will doubtless suggest themselved to those skilled in the art withoutdeparting from the scope of the appended claims.

I claim as my invention:

1. A combined recording and reproducing unit comprising a vibratorymember carrying a pair of separate holders projecting at a divergingangle of at least ninety degrees, a recording stylus supported in oneholder and a reproducing stylus supported in the other holder thediverging relation of said styli causing them to be widely separated foreasy access, and mechanism for operating said member and recordingstylus in accordance with transmitted electric impulses, the operationof said member by the reproducing stylus causing said mechanism toproduce electric impulses.

2. In phonographic apparatus, the combination of an arm supported on oneend to swing horiz-ontally over a record, a combined recording andreproducing unit mounted on the other end of said arm, and a Weightadjustably carried by said arm and movable either over said unit duringthe recording operation or over the supported end of the arm during thereproducing operation.

3. In phonographic apparatus, the combination of an arm supported on oneend to swing horizontally over a record, a combined recording andreproducing unit mounted on the other end of said arm, and a weightpivotally connected to said arm at an intermediate point of the arm,

whereby said weight may be swung over said unit or over the supportedend of said arm.

4. In phonographic apparatus, the combination of an arm supported on oneend to swing horizontally over a record, a combined recording andreproducing unit mounted on the other end of said arm, a lever hinged atone end to said arm at a distance from said casing, and a weight securedto the free end of said lever, whereby said lever may be swung forwardto place the weight on top of said unit or swung rearward to place theweight on the supported end of said arm.

5. In phonographic apparatus, the combination of an arm supported on oneend to swing horizontally over a record, a combined recording andreproducing unit mounted on the other end of said arm, a lever hinged atone end to said arm at a distance from said casing, a weight secured tothe free end of said lever, whereby said lever may be swung forward toplace the weight on top of said unit or swung rearward to place theweight on the supported end of said arm, and means for adjusting thehinge connection of said lever axially of said arm.

6. An electric phonograph reproducer comprising a U-shaped magnet, apair of polar extensions carried by said magnet, a coil on at least oneof said extensions, a vibratory support adapted to be actuated by areproducing stylus, an armature unit carried by said support, saidarmature unit consisting of a pair of spaced magnetic arms arrangedcrosswise of said polar extensions and forming variable airgapstherewith, said bars beingA arranged on opposite sides of said coil andon opposite sides of said polar extensions.

7. A combined recording and reproducing unit,

comprising electromagnetic mechanism provided with a vibratory armature,a, recording stylus carried by said unit and mechanically connected tosaid armature to be operated thereby in accordance with electricimpulses transmitted through said mechanism, a separate reproducingstylus carried by said unit in diverging relation to said recordingstylus and mechanically connected to said armature to vibrate saidarmature which thereby generates current impulses in said mechanism, andmeans whereby said unit is adjustable to bring either stylus intooperative position.

8. An electric phonograph reproducer comprising a casing, an arm pivotedto said casing, an armature carried by said arm, a stylus member forvibrating said armature, means for converting the movements of saidarmature into electric impulses, and elastic pads carried by said casingand engaging opposite sides of said arm in pressure contact, wherebysaid pads damp the movements of said arm and hold the same inpredetermined normal position, said pads being located at a distancefrom said armature and out of contact therewith.

9. An electric phonograph reproducer comprising a casing, an arm pivotedto said casing, an armature carried by said arm, a stylus member forvibrating saidarmature, means for converting the movements of saidarmature into electric impulses, a pair of sockets mounted in oppositesides of said casing and adjustable toward and away from each other, andelastic pads held in said sockets and engaging opposite sides of saidarm in pressure contact, whereby said pads damp the movements of saidarm and hold the same in predetermined normal position, said pads beinglocated at a distance from said armature and out of contact therewith.

10. In phonographic apparatus, a combined recording and reproducing unitcomprising a vibratory member, a recording stylus and a reproducingstylus both carried by said member and extending in differentdirections, a support on which said unit is adjustable tobring eitherstylus into operative position on a record, electric mechanism forvibrating said member in accordance with transmitted impulses to actuatesaid recording stylus, said mechanism being adapted to convert themovements of said member by the reproducing stylus into electricimpulses, and a weight adjustably mounted on said support to make thepressure on the recording stylus greater than that on the reproducingstylus.

11. A combined recording and reproducing unit comprising a casing,electromagnetic mechanism in said casing, said mechanism including acoil and an armature adapted to vibrate in accordance with currentimpulses passing through said coil during the recording operation, themovements of said armature during the reproducing operation generatingcurrent impulses in said coil, a vibratory member connected with saidarmature, and a pair of stylus members carriedby said member forrecording and reproducing respectively, a movable arm on which saidunit-is supported, and means whereby the supported unit is rotatablyadjustable about the longitudinal axis of said arm to bring eitherstylus member into operative position.

12. A combined recording andA reproducing unit for disk records, saidunit comprising a casing, electromagnetic mechanism in said casing, saidmechanism including a coil and an armature adapted to vibrate inaccordance with current impulses passing through said coil during therecording operation, the movements of said armature during thereproducing operation generating current impulses in said coil, avibratory member pivoted at the center and connected to said armature, arecording stylus carried at one end of said member, a reproducing styluscarried at the other end of said member, said unit being adjustable tobring either stylus into operative position, a horizontally swinging armon which said unit is operatively mounted, and a swivel connectionbetween said unit and said arm to permit rotation of the unit through apredetermined arc for bringing either stylus into operative relation toa disk record.

13. In phonographic apparatus, the combination of a supporting armmounted at one end to swing horizontally over a record, a casingattached to the other end of said arm and rotatable about thelongitudinal axis of said arm through a lpredetermined arc to either oftwo operative positions, a recording stylus and a reproducing stylusprojecting from said casing and each adapted to be brought intooperative relation to a record by the rotary adjustment of said casing,and mechanism in said casing for operating said recording stylus inaccordance with transmitted electric impulses, the movements of saidreproducing stylus causing said mechanism to produce electric impulses.

14,. A combined recording and reproducing unit for operating on the sametype of record, said unit comprising a casing, electromagnetic mechanismin said casing, said mechanism including an armature bar pivoted at thecenter and adapted to vibrate in accordance with electric impulsestransmitted to said mechanism during the recording operation, themovements of said armature also causing said mechanism to produceelectric impulses during the reproducing operation, a vibratory memberconnected intermediate between its ends to the center of said armature,a recording stylus carried at one end of said member, and a reproducingstylus carried at the other end of said member for reproducing from thesame type of record on which said recording stylus operates, said casingbeing adjustable to bring either stylus into operative position.

15. A combined recording and reproducing unit for operating on the sametype of record, said unit comprising a casing, a laterally twistablespring blade supported at its ends in said casing, a vibratory armaturebar connected at the center to the center of said spring blade,electromagnetic mechanism operatively associated with said armature tovibrate the same in accordance with transmitted electric impulses, saidmechanism being also adapted to produce electric impulses by themovements of said armature, an arm connected intermediate between itsends to the center of said spring blade and projecting out of saidcasing, a holder at each end of said arm, a recording stylus mounted inone holder, and a reproducing stylus mounted in the other holder forreproducing from the same type of record on which said recording stylusoperates, said casing being adjustable to bring either stylus intooperative position.

16. In phonographic apparatus, the combination of a supporting armmounted at one end to swing horizontally over a record, a casingattached to the other end of said arm and rotatable about thelongitudinal axis of said arm through a predetermined arc, a recordingstylus and a reproducing stylus projecting from said casing and eachadapted to be brought into operative relation to the same type of recordby the rotary adjustment of said casing, `mechanism in said casing foroperating said recording stylus in accordance with transmitted electricimpulses, the movements of said reproducing stylus causing saidmechanism to produce electric impulses from the same type of record onwhich said recording stylus operates, and means carried by said arm forexerting additional pressure on the recording stylus during therecording operation, said means being adjustable to remove said addedpressure from the reproducing stylus.

17. In phonographic apparatus, the combination of an arm supported atone end to swing horizontally over a disk record, a casing mounted onthe other end of said arm and rotatable thereon through a predeterminedarc to either of two operative positions, a vibratory member carried bysaid casing and supported substantially at the center to vibratelaterally in either position of the casing, a stylus holder at each endof said member, a recording stylus in one holder and a reproducingstylus in the other holder, said recording stylus being in operativeposition when said casing is turned one way and said reproducing stylusbeing in operative position when the casing is turned the other way,said two styli being constructed to record on and reproduce from thesame type of disk record, and mechanism in said casing for operatingsaid vibratory member and recording stylus in accordance withtransmitted electric impulses and for converting the vibrations of saidreproducing stylus and member into electrical impulses.

18. In phonographic apparatus, the combination of an arm supported atone end to swing horizontally over a record, a casing mounted on theother end of said arm and rotatable: thereon through an arc ofapproximately 180 degrees to either of two operative positions, avertical member arranged at the front end of said casing in alignmentwith said arm, means in said casing for supporting said membersubstantially at the center to vibrate laterally, a stylus holder ateach end of said member, a recording stylus in one4 holder and areproducing stylus in the other holder, said recording stylus being inoperative position when said casing is turned one way and saidreproducing stylus being in operative position when the casing is turnedthe other way, said two styli being constructed to record on andreproduce from the same type of record, and mechanism in said casing foroperating said vibratorymember and recording stylus in accordance withtransmitted electric impulses and for converting the vibrations of saidlreproducing stylus and member into electrical impulses.

19. In phonographic apparatus, the combination' of an arm supported atone end to swing horizontally over a'record, a casing mounted on theother end of said arm and rotatable thereon through an arc ofapproximately ninety degrees to either of two operative positions, arightangled lever pivoted at the center to said casing and projectingtherethrough, a stylus holder at each end of said member, a recordingstylus in one holder and a reproducing stylus in the other holder, saidtwo styli being constructed to record on and reproduce from the sametype of record, said recording stylus being in operative positionwhensaid casing is turned one way and said reproducing stylus being inoperative position when the casing is turned the other way, a iinger insaid casing connected to the pivoted center of said lever, a magneticarmature carried by said finger, and electromagnetic means for vibratingsaid armature and recording stylus in accordance with transmittedelectric impulses, the vibrations of said armature by the reproducingstylus causing said electromagnetic -means to produce current impulses.

20. In phonographic apparatus, the combination oi' an arm supported atone end to swing horizontally over a record, a casing mounted on theother end of said arm and rotatable thereon o casing is turned one wayand said reproducing stylus being in operative position when the casingis turned the other way, mechanism in said casing for operating saidvibratory member and recording stylus in accordance with transmittedelectric impulses and for converting the vibrations of said. reproducingstylus and member into velectrical impulses, and means carried by saidarm for exerting additional pressure on the recording stylus during therecording operation, said means being adjustable to remove said addedpressure from the reproducing stylus.

ADOLPH A. THOMAS.

